Symlink-ing into addons folder
Rather than using a symlink you can just point to a /scripts/ directory in User Preferences > File



After setting the path be sure to Save User Settings. Doing this will let you place your scripts in the folder designated, and leave the default folder alone.

Your folder structure should look like:

scripts/
  addons/
  addons_contrib/
  startup/
  presets/


Not all sub-directories are required, but you should have at least /scripts/addons/